linux-phytec-fsl

drm/exynos/fimc: replace mutex by spinlock

Function fimc_dst_set_buf_seq is called by irq handler
so it should not use mutexes. This patch fixes it.

Signed-off-by: Andrzej Hajda <a.hajda@samsung.com>
Signed-off-by: Inki Dae <inki.dae@samsung.com>